Controlled deposition of Pt nanoparticle size modified TiO₂ nanotubes arrays for enhanced indoor air treatment

Air pollution remains a significant global health challenge, with contaminants like volatile organic compounds (VOCs) and pathogenic bacteria serving as a major contributor. Titanium dioxide nanotubes (TiO₂-NTs) have emerged as promising materials for air purification, owing to their high surface area, photocatalytic activity, and stability. In this context, this study investigates the controlled electrodeposition of platinum (Pt) nanoparticles onto TiO₂-NTs to enhance their photocatalytic properties for indoor air treatment applications. By optimizing the Pt nanoparticle size and distribution, we aim to improve the degradation of VOCs and the inactivation of airborne bacteria. A series of Pt/TiO₂-NTs catalysts with varying Pt nanoparticle sizes were synthesized via electrodeposition onto TiO₂-NTs fabricated via anodization of titanium foil. The structural and optical properties of the modified nanotubes were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL). The resulting materials exhibited enhanced photocatalytic degradation of VOCs and effective inactivation of Escherichia coli (E. coli) under visible light irradiation, attributable to the synergistic effects of Pt and TiO₂-NTs. Notably, catalysts decorated with smaller Pt nanoparticles (10-22 nm) demonstrated the highest photocatalytic activity, emphasizing the critical influence of nanoparticle size on performance.